Climate change can directly influence groundwater systems through modification of recharge. Affecting not only groundwater levels and flow dynamics, climate change can also modify the fragmentation and hierarchy of groundwater flow systems. In this study, the influence of climate change-impacted recharge on groundwater levels and on interconnected groundwater flow patterns is evaluated. Special emphasis is placed on how flow system hierarchy may change, to examine possible consequences on groundwater-related shallow surface water bodies and on groundwater-surface water interaction. As a test site with no significant anthropogenic impacts, the Tihany Peninsula in Hungary was an ideal area for the study. We address the following issues: i) How might a groundwater system, including groundwater-surface water interaction, be modified by predicted climate change?, ii) Given the variable groundwater levels and flow patterns, how will the water levels and fluxes be impacted around surface water bodies?, and iii) How sensitive are groundwater-related wetlands to these changes, and will they be maintained or will they eventually disappear? In order to answer these questions, two-dimensional transient numerical simulations were performed based on site-specific measurements and climatic prediction at the Tihany Peninsula. Results show that future climate trends can cause dynamic evolution and dissipation of transient groundwater flow systems, and the characteristic flow system hierarchy can change from nested flow systems to a set of single flow cells. Preservation of associated groundwaterdependent ecosystems would be challenging under these conditions since long-term climate change could potentially have serious consequences, including wetland disappearance. Understanding these transient processes in two-dimensions can also help to setup three-dimensional site-specific models.

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The fluid evolution of the Buda Thermal Karst (BTK) has been ongoing since the Late Miocene. At that time the system was fully confined and only the thermal buoyancy influenced the flow of fluids in the system. Parallel with the uplift of the Buda Hills, the infiltration of fresh water into the system began; thus the subsequent evolution of the topography-driven groundwater flow brought about the superposition of the two fluid flow systems. This occurred with different prevailing driving forces: namely, the topography in the upper part and buoyancy in the lower. The uplift of the Gödöllő Hills also had an influence on the processes of the BTK and resulted in the evolution of fluid flow heading from the eastern, confined part of the system towards the River Danube. Consequently, the dominantly basinal fluids of the confining strata infiltrated into the underlying carbonate aquifers filled with meteoric water via vertical leakage. These changes were followed in the mineral paragenesis of the BTK. The western region of the BTK is part of the NE Transdanubian Range and nowadays the carbonate aquifers are semi-or unconfined. The springs of this area represent the terminal points of local, intermediate and regional flow systems and they display the rock-water interaction along the flow path. The evaluation of the flow pattern could reveal the West-East direction of flow under the River Danube and the upwelling of fluids towards the discharge areas along the River Danube in the upper, shallow part of the system. The NaCl-type basinal fluids originated from the eastern-confining layers and they contribute to the regional flow component. West-Southwest of the River Danube, Mg 2+ -and SO 4 2 -rich water can be found. The results represent the hydraulically continuous flow sytem of the BTK, the asymmetric flow pattern at the boundary of unconfined and confined carbonate aquifers and, moreover, the significance of confining layers in the accumulation and dissipation of heat. The pressure conditions present in the system are nearly hydrostatic. The NE Marginal Fault also has a role in the differentiation of the discharge areas at the foothills of the Rózsadomb and the Gellért Hill. In the area behind the Gellért Hill an intermediate flow system appears; therefore, at the foothills of the Gellért Hill only thermal water is discharged. At the Rózsadomb the lukewarm and hydrothermal fluid discharge areas are close to each other. Thus the evidence strongly suggests that the respective hydrothermal components of the Central and Southern systems differ. The NaCltype water of the eastern half of the basin contributes to the discharge of the regional flow path of the Central system. This system transfers H 2 S and CH 4 to the springs. In the case of the Southern System, the excess of sulphate in the water is more prevalent, and this may be in connection with the evaporite layers in the SW. On the basis of sulphur isotope analysis, the meteoric fluid component of the Rózsadomb receives its sulphur during infiltration through ...

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Abstract. The chemical properties of tar ball (TB) particles generated from dry distillate (wood tars) of three different wood species in the laboratory were investigated by analytical techniques that had never been used before, for their characterization.The elemental composition of TB particles from three tree species were very similar to one another and to those characteristic for atmospheric tar balls (TBs) collected from savanna fire during the SAFARI 2000 sampling campaign. The O/C and H/C molar ratios of the generated TBs were at the upper limit characteristic for soot particles. The FT-IR spectra of the generated TBs were 15 very similar to one another as well and also showed some similarity with those of atmospheric humic-like substances (HULIS).The FT-IR measurements indicated that laboratory-generated TBs have a higher proportion of aromatic structure than HULIS and the oxygen atoms of TBs are mainly found in hydroxyl and keto functional groups. Whereas the starting materials of the TBs (wood tars) were Raman inactive in the range of 1000-1800 cm structures and disorder in them, respectively. In the Py-GC-MS chromatograms of the laboratory-generated TBs mostly aromatic compounds (aromatic hydrocarbons, oxygenated aromatics and heterocyclic aromatics) were identified in accordance with the results of Raman and FT-IR spectroscopy. According to OC/EC analysis using EUSAAR_2 long thermal protocol, 22% of the total carbon content of laboratory-generated TBs was identified as elemental carbon (EC), contrary to expectations based on the current understanding that negligible if any EC is present in this sub-fraction of the brown carbon family. Our results suggest that 25 spherical atmospheric TBs with high C/O molar ratios are closer to BC in many of their properties than to weakly absorbing HULIS.